大佬帮我看看这个二维数组，我看不懂 if 语句想要表达什么意思

#include <stdio.h>
int main()
{   int  i  , j ,x =0 ,y = 0 , m ;
int  a[3][3] = { 1, -2 , 0 , 4 , -5 , 6 , 2 , 4 };
m = a [0][0] ;
for (i=0 ;i < 3 ;i++)
              for (j = 0 ; j<3 ; j++ )
                 if ( a[ i] [ j ] >m )
                 {  m = a[ i ][ j ] ;
                    x =  i ;
                    y = j ;
}
             printf(" ( % d  , % d ) = % d \n", x , y, m );
         return 0;
}